Electric lamp.



A. D. COX.

ELECTRIC LAMP.

APPLICATION FILED DEC.22.1915.

1 ,2 11. 5, 1 1 8. Patented Feb. 6, 1917.

a) l m 4 WITNESSES I IIVVEIVTOR 9 4p, 191.5527? 17. Fax,

ATTORNEYS ALBERT now cox,

F WIN TERVILLE NORT H CAROLINA.

' ELECTRIC LAMP.

Specification of Letters Patent.

Patented Feb. 6, 191?.

Application filed December 22, 1915. Serial No. 68,195.

To all whom it may concern:

Be it known that I, ALBERT D. Cox, a States, and a resident State ofNorth'Carolina, have invented a Electric Lamps, of

arranged to be brought into 'anism and certain new and usefulImprovement in which the following is a specification. y I

My invention relates to improvements in incandescent electric lamps, andit consists in the combinations,constructions, and arrangements hereindescribed and claimed.

An object of my invention is to provide a lamp having twoseparateresistance or light giving circuits, one of these circuits beingoperation prior to the other, so that in a case of the burning out ofthe filament of the first circuit, the second circuit may be. broughtinto use, thereby increasing the life of the lanip.

A, further object of my invention is to provide a device of the typedescribed in which the switching of the current through the secondcircuit is accomplished by means of a partial turn of the lamp, thusdoing away with any complicated switching mechalso obviating thenecessity of removing the lamp from the socket.

A further object of my invention is to provide a lamp having twolighting circuits one candle power or one double that candle features ofthe invention .will beparticularly till power. I

Other objects and advantages W111 appear in the following specification,and the novel pointed out in the appended claim.

My invention is illustrated in the accompanying drawing forming part ofthis application, in which:

Figure 1- is a sectional view lamp.

Fig. 2 is a perspective view showing the filament support, and

Fig. 3 is a sectional view of a portion of the device showing the springcontact member in a shiftedposition. a

Fig. 4 is a diagrammatic view showing the circuit connection.v

In carrying out my invention I provide a central filament support 1 ofany suitable shape, but preferably of the shape shown in through the andbears at one end a series of outwardly 5 in a little. farther,

' extending arms 2 which support a filament 3. One end of this filamentis connected by a conductor 4 with the exterior conducting portion of ascrew plug 5, the support 1 being preferably embedded in the plug bymeans of a suitable filling 6 such as plaster of- Paris or the like. Theopposite end of the filament 3 is connected by a conductor 7 with aterminal or contact 8 disposed at the end of the support. This contact8, it will be observed, is in the form of a spring having a lateral bowor bend at its central portion.

The support 1 is provided with a second set of laterally extending arms9, these arms supporting a filament 10, one end of which is connected bythe conductor 11 with the.

end is firmly secured to the screw plug 5/ The latter is designed to fitany standard socket 15 so that when it is screwed into the socket, thelamp will be retained firmly in position. The bowed portion 8 of thespring contact 8 is not only at the center of the spring but at thecenter of the screw plug, that is to say, on the axial line of the lamp,so that when the lamp is screwed in, the portion 8 comes into engagementwith the contact 14. pass through contact 8, conductor 7, filament 3,and by conductor 1 back to the screw plug- 5, thereby causing thelighting- 'of the lamp by means of the filament 3.

This condition is shown in Fig. 1, and it will be obvious that thefilament 10 may be brought into circuit so that the contact 8 willengage the contact 13, whereupon part of the current will flow throughthe contacts 8 and 13, conductor 12, filament 10, conductor 11, to theconducting portion of the plug 5.- With both filaments in circuit, thelamp of course will give double the drawing. This filament support ismade of suitable insulating material, such as glass candle power. It isonly necessary to turn the plug a portion of a revolution in order tobring the contacts 8 and 13 together.

This causes a current to arranged to engage the central by screwing theplug This may be done by anyone and thus obviate the necessity ofthrowing a switch.

One of the advantages of this device is that the life of the lamp isvirtually doubled, since one filament may give normal Another advantageof the lamp is that. in cases Where extra light is needed itmay be hadat any time by a partial turn of the lamp.

In Fig. 4: I have shown a modified form in which the end. filamentcarried by the arm 2' is connected with a button 13 while the. otherfilament carried by the arm 9' is connected with the spring 8' Thelatter filament therefore lights up first and the filament carried bythe arm 2 lights up after the lamp has been screwed up farther. I mayuse either arrangement without departing from the spirit and scope ofthe invention.

I am aware that lamps having separate filaments are not new, and suchbroadly.

I claim I {do not claim An incandescent electric lamp compris-.

ing aninsulating filament support, two.sets of laterally extending.armscarried by said support, a filament carried by, each of said sets ofarms, a screw plug secured to one end of said insulating support, saidscrew plug having a pair of contact surfaces and an inner fillingbetween said contacting surfaces and said insulating support, a

spring contact having a bowed contact portion, said spring contact beingsecured to theend .of the insulatlng support adjacent to the screw plugand beingconnected to one 7 of said filaments, the other terminal of thefilament being connected with theconduCting portion of the screw plug, acontact button carried at the .same end-of said in sulating support andarranged to be engaged by said spring contact, said contact button beingconnected with the other of said filaments, the opposite terminal ofsaid last named filament being in electrical connection with thecontacting surface of the screw plug, and a'bulb inclosingsaidfilaments.

ALBERT DOW COX;

Witness:

J. L. RoLLINs.

